Someone (most likely a family member) who immediately opens your bedroom door after knocking before you have a chance to answer. The same way a doctor does after the nurse leaves you waiting in a room for 20 minutes.
Mom: Why do you keep your door locked?
Son: Because everyone who lives here is a fucking doctor knocker.
Son: Because everyone who lives here is a fucking doctor knocker.
by Brain Mountain August 16, 2016
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